Wind turbine rotor blades include lightning protection arrangements for diverting lightning currents, which lightning protection arrangements comprise multiple electrically conducting components, for example lightning receptors and lightning conductors. In the case of a lightning strike, very high currents flow through these components for a very short time, which can result in high potential differences on account of electromagnetic induction. In order to avoid flashovers between the different components and consequently resultant damage to the wind turbine rotor blade, equipotential bonding connections are produced, as a rule, in particular between conductors that are arranged in parallel. Potential differences are equalized by means of the connections. At the same time, where applicable, they can cause a lightning current to divide into multiple components or can guide the entire lightning current. Two fundamentally different methods have been disclosed to produce the equipotential bonding connections.
On the one hand, connection conductors arranged in the interior of the wind turbine rotor blade can be used. U.S. Pat. No. 7,651,320, for example, shows a wind turbine rotor blade with lightning receptors in the form of metal threaded bolts which are arranged in a rotor blade wall and are screw-connected to various connecting elements. These include connection conductors which are fastened to a web and in each case connect together one lightning receptor on a suction side and one lightning receptor on a pressure side. At the same time, the connection conductors are connected to electrically conducting main spar caps.
On the other hand, it is possible to create an equipotential bonding connection which is arranged on the outside of the wind turbine rotor blade. An example has been disclosed in EP 2 930 358 A1, in which lightning conductors arranged on the pressure and suction side are connected by means of equipotential bonding bars which are guided around the profile trailing edge.
U.S. Pat. No. 8,182,227 has disclosed a wind turbine rotor blade with lightning receptors which are integrated into a wall of the wind turbine rotor blade. In one embodiment, one of the lightning receptors comprises a removable portion which closes an access opening to an interior of the wind turbine rotor blade. A connection conductor, which extends along a web in the interior of the wind turbine rotor blade, is to be able to be fastened through the access opening on a lightning receptor which is situated opposite the access opening.
WO 2014/200333 A1 has disclosed a device for fastening a lightning receptor on a wall of a wind turbine rotor blade. An inner and an outer fastening element is used for this purpose. The lightning receptor can either be fastened on the inner fastening element from the outside of the rotor blade, or together with the inner fastening element, on the outer fastening element from the inside of the rotor blade.